Method of heating and cooling plastic material and apparatus therefor



Aug. 19 1924.

A. DE L. SMITH METHOD OF HEATING AND COOLING PLASTIC MATERIAL AND APPARATUS THEREFOR s-Shet 1 2 Sheet Filed Feb. 20, 1924 .Lw' ATTORNEYS Aug. 19, 1924. I 1,505,671 A. DE L. SMITH METHOD OF HEATING AND COOLING PLASTIC MATERIAL AND APPARATUS THEREFOR Filed Feb. 20, 1924 2 Sheets-Sheet. 2

r- YE A ATTORNEYS Patented Aug. 19, 1924. I I

lED' STATES PATENT ANNESLEY DE LOS SMITH; or MOUNT van-non, new YORK.

METHOD or HEATING AND COO ING esteem anathema jinn Marianne THEREFOR.

I Application filed-February 20, 1924. sea1m;69i,1 i.

T9 all wham. it may 07165701, g Su -bjcted lilthe alternate" appl'lCa'tl'OH O f Be it known that I, ANNnsLnY Danes heating and 'cdoling'media. l 7 SMITH, a citizen of the United States, re- Another object of the invention is to pro- I siding at Mount Vernon, in the county of vide fer' expansion "and contraction ofthe 5 \iVestchester, State of New York, have inheated enameled-portion of the plate in-- vented certain new and useful Improvements dependently of the surrounding portion 60 in Methods of Heating and Gooling Plastic thereof. v i

Material and Apparatus Therefor; and I To secure equalization of temperature the do hereby declare the folloiving to be a, heati-ngandcool-ing media are conducted to 10 full, clear, and exact description of the in the central area of thesurface to be treated,

vention, such as'vvillenable others skilled in but instead of traveling thence outwardly 65 the art to which it appertainsgfto make and in paths which are annular as in plates use the same. v heretofdre used the ,path' of tre-vel ofthe This" invention relates to a method of'and media is; according to "my invention; sub

apparatus for heating and cooling plastic stant'ially radial/Grimm the centerto the material in molding presses and is par; circumference. -Moreovei,- to ensure uni- 7 0 ticularly adapted'for the manufacture of form heatingl prefer 'to cause them'e'dia sound-reproducing records. lt may be utito travel successively in transverse dime-- lized also Wherever it is desirable to alter" tions Within the plate from the face to the nately and rapidlyheatand cool -mate'rials backthe'reof; thejheating and cooling of a plastic or semi-plastic nature. operatidns; therefore, the respective medium 75 i In the manufacture of sound-reprodiicing moves" in all dirgcnonef sm the center of records dies are mounted in a suitable press the 'plate toward the periphery and at the p I upon supporting plates which are provided same time it is directed"rep'eatedlytoward with passages for steam and cold water, the face and back. of the plate. -As the" The d-ies' are thus heated by the steal-n and medium successively fills the passages Within :0

the mass of plastic dough is placed between" the plate, its travel is not extended, as in them. Pressure is then applied to form the the case oi: annular or spiral passages; so record and cold Water is admitted to the theta marked difference in temperature 625- passages to chill the material-.- As the press ists between the opposite ends of the passage.

opens steam is again admitted to heat the canbe demonstrated readily that the 85 dies in preparation for the next operation. distribution of the heating and cooling lhe successive heating and chillingofthe" media as described is more rapid and effi: I dies is conducted as rapidly "as possible in cientthan has been possible with ,anyother" maintaining maximum produc'tien; f'Go'nsearrangement of. distributing passages bequently the metal of the plates is subjected ceuse the heating anclc'ooling surfaces arejso to severe stresses; L increased and the amounts of heating and A more serious difliculty than the des'trliccooling media required to accomplish the tive effect of alternate heating a'nd cooling purpose of the invention are" reduced: p i

40 is that of obtaining uniformity otheating Moreover, thefaceand back of the plate and cooling. Numerous attemptshave beenquickly brought to a uniform temperature 95 made to secure uniformity of he'atdistribi'iand dangerous-stressesare thereby atoidedQ tion by the arrangement of tn passage in Therapid distribution of the heating and the die-supporting plates but equalization of cooling media ensures substantial equalizathe temperatures at various parts of the dienon, of the temperature at all parts of the supporting plates has never been ac'c'om- 7 surface which is' in contact w'ith the die. 1 I

plished heretofore. I v I {This is a verymaterial advantage since it It is the Ob ect of the present inventlon ensures uniformly plastic material and conto provide a method of and apparatus for sequ'ent'ly it permits "the most rapid and I heating and cooling dies and'the'like which successful productionf'of sound reprotlucing permits substantial equalization of the tem-] records and sim 'lar'obwctsy peratures' at all parts ofthe die ina rapid 1 ltxis'to be understood that While dies for p I l and effective manner andwhich reduces the sound-reproducing records are generally stresses to Which thediesup'portlng plate is circular; the terms radial annular" as s is heated and cooled.

used herein are not intended to limit the invention to circular heating and cooling plates. By a simple adaptation and rearrangement. of the passages it may be applied with like advantages to rectangular plates.

The die-supporting plates which are used in the manufacture of sound-reproducing records are generally rectangular in form and include a substantial amount of metal in excess of that portion of the plate which I The inner and outer portions of the plate do not expand and contract to the same extent and consequently stresses are set up in the metal which tend to rupture the plate after. more or less, extended use. To avoid this difliculty I proi 'vide a narrow channel in the face of the plate surrounding the inner portion of the plate but not extending through to the back thereof. This channel'can be formed by a milling cutter or otherwise or the central portion of the plate can be made as aseparate part and welded to the outer portion, leavin a channel as described. The narrow cliannel permits the inner portion of the plate to expand independently of the outer portion and avoids the stresses mentioned. V In carrying out the invention in its preferred embodiment a supporting plate is provided for each die. Each plate comprises, preferably, two parts which are welded together to form a unitary structure. The parts of the plates are provided with interfitting ribs and channels which form the baffled passages through which the heating and cooling media travel from the inlet to the outlet. The inlet is arrangedto carry the media to the central region of the plate where a channel is formed with a sloping bottom which directs the media gradually toward the face of the plate to avoid causing'a hot or cold spot thereon. As soon as the heating or cooling medium fills the central channel it. travels transversely about the adjacent rib on the face portion of the plate toward the rear I plate to avoid the discharge of the heating thereof and thence through a plurality of radial openings provided in the rib into a surrounding channel. The second channel. is quickly filled with the medium which then travels about the next rib and through radial openings asbefore until the outer channel is filled. 'Theopenings to the outer channel are disposed only at the inlet side of the or cooling media before it has heated or cooled the outer zone of the plate. The medium escapes from the outer channel; through the outlet., The radial openings between the successive channels may be in alignmentor staggered, the latter arrangement being perhaps advantageous.

The distribution ofthe heating or cooling medium through the plate is almost instantaneous as it enters under pressure and the passages are designed to permit rapid travel from the central to the. outermost channel. Owing to the large amount of metal surface which is exposed to the media in the plate heating and cooling are both rapid and uniform.

To permit relative expansion and contraction of the inner and outer portions of the plate I provide a slot which is preferably milled or otherwise formed in the face of the plate. The-slot is very narrow and is covered by the clamping ring which holds the die in place on the face of the plate. If the slot is cut in the plate it need not cross the inlet and outlet passages and consequently no leakage can occur if the pipes through which the media are introduced and withdrawn communicate merely with the outer ends of these passages. The central portion of the face of the plate may, however, be made as a separate part and welded to the. outer support at the back. In that case the slot is not cut but is formed by making the face portion of the plate somewhat smaller in diameter than the inner diameter of the. outer support The inlet and outlet passages are then reamed and the pipes conveying the heating and cooling media are threadedly or otherwise connected to the extensions of these passages in the central portion, thus avoiding leakage. Y

The invention will ;be further described with reference particularly to plates for. manufacturing sound-reproducing records as illustrated in the accompanying drawing, in which 7 Fig. 1 is a section on the line 1-1 of Fig. 3;

Fig. 2 is a section Fig. 3;

Fig. 3 is a section on the line .33 of Fi n2; and 7 la ig. 4 is a detail in section.

Figure 5 is a plan view of the face portion of the. plate.

Figure 6 is a section in perspective of back portion of the plate.

Referring to the drawing, 5indicates the face and 6 the back of a heating and cooling plate which'is made in two parts of steel or other suitable metal capable of withstanding the stresses due to heating and cooling and the relatively enormous pressures which are used in forming plastic materials. The face portion 5 of the plate is provided with on the'line 2-2 of *a plurality of annular channels or grooves the ttaam P ev t escape f h hefeting a d re nga- T k p m-9n. 6 0f the peas fl ge a l a 12am e flanges est against shoulders '18 and 1A on the face pori f p The adja en areas a cut t m s'rQQ s which are fi ed in welding the portions pf the plate, The welding is preferably accomplished with an Ox yl o ch er y-t e electri a and the parts of the plate are joined by ing h e ia en aerfaaes and Welding rod to form a unitarystru cture. The flanges 11 and 12 prevent any molten material from entering the channels of the plate.

A passage 15 which extends through all of the ribs on the face and back portions of the plate conducts the heating and cooling media to the central channel. The rib on the back portion of the plate which projects into this channel is made with a sloping face 16 which directs the media gradually toward the face of the plate so that the heating or cooling may not be too abrupt at the start.

The ribs 8 on the face portion of the plate seat in the bottoms of the grooves 9 of the back portion of the plate and prevent com-. munication between the grooves except through openings 17 which are provided at intervals in the ribs. These openings may be opposite each other or may be staggered.

In the outermost rib 8 only two openings 17 are provided so that all of the heating and cooling media are delivered to the outermost channel on the inlet side of the plate.

When steam or cold water is admitted to the central channel it passes about the ribs into the next channel and thence through the channels successively in all directions from the central to the next to the outermost channel. It then escapes to the latter channel and through an outlet 18. Rapid heatin and cooling of the plates are thus assure A slot 19 is shown in the face of the plate and extending to a substantial depth therein. The slot is not cut through the inlet and outlet passages 15 and 18 in this form of the invention. It is of suiiicient width to permit expansion of the inner portion of the plate without subjecting the outer portion to stress and consequently prolongs the life of the plate. As hereinbefore indicated, the slot can be formed otherwise than as shown.

Various changes can be made in the details of construction of the plate without departing from the invention or sacrificing any of the advantages thereof.

I claim 1. The method of uniformly heating and pre sure, which compr se od cing" t e eat ng nd c o ing d te th c ntral region of th a a toibe trea and Pe mitting theymedia to expand substantially radial directions therefrom. s

. 2. The method of uniformly heating and cooling plastic materials in molding under Pres er? which mp i e intr diw n e heating n coo ing med a th n r l of the area to be; treated and permit-' ting the media toexpand in substantially radial directions therefrom, the media being a fe ea i d t tra a t nate y away f om and toward thefmaterial. A

3. The method of uniformly heating and cooling plastic materialin molding under pressure, which comprises introducing the heating and cooling media at the central region of the area to be treated, directing the media alternately away from and toward the material and permitting it toexpandin substantially radial directions to the surrounding regionsof the area.

4;. heating and cooling plate to support a die in molding plastic material comprising complementary parts having alternating ribs and channels communicating in radial directions and a passage to deliver the heating and cooling media to the central channel.

5. A heating and cooling plate to support a die in molding plastic material comprising complementary parts having alternating ribs and channels. with openings in the ribs on one of the parts to provide communication between the channels in radial directions and a passage to deliver the heating and cooling media to the central channe 6. A heatin and cooling plate to support a die in molding plastic material comprising complementary parts having alternating ribs and channels, the ribs on one of the parts seating in the bottoms of the channels on the other part and having openings to provide communication between the channelsin radial directions, the plate having a passage to deliver the heat-ing and cooling media to the central channel.

a die in molding plastic material comprising complementary parts having alternatcee n P astic me e a i n m ld ng und r a I of heating and cooling media therethrongh; said plate having a slot to permit expansion ing ribs and channels and a passageto deof the inner portion relatively to the outer portion.

10. A heating and cooling plate to support a die in molding plastic material comprising'inner and outer portions, the former having means permitting distribution of heating and cooling media therethrough,

'- the outer portion being spaced from the inner portion at the face of the plate to permit independent expansion of the inner portion.

In testimony whereof I afliX my signature.

ANNESLEY DELOS SMITH. 

